Albert Barnes Commentary 2 Kings 13:18

"And he said, Take the arrows; and he took them. And he said unto the king of Israel, Smite upon the ground; and he smote thrice, and stayed." — 2 Kings 13:18 (ASV)

Smite upon the ground - Some prefer to render this as: “Shoot to the ground;” that is, “Shoot arrows from the window into the ground outside, as if you were shooting against an enemy.”